CSCW systems have generally failed to meet the requirements of users in actual cooperative work settings, primarily due to constraints imposed by current platform architectures that do not adequately support the fluent transitions between formal and informal interaction or the inextricable interweaving of individual and cooperative work that characterizes everyday work practice. Based on a sociological conceptualization of cooperative work, the paper outlines the requirements for a CSCW platform that is characterized by a clear division of labour between CSCW applications that incorporate domain-specific mechanisms of interaction and a CSCW platform providing a set of generic techniques of communication accessible to CSCW and singleuser applications alike.